1. Field of the Invention
The present invention concerns a method as well as an apparatus for automatic detection of anomalies in vessel structures, in which a 3D volume data set of an imaging 3D measurement of the vessel structure is obtained and characteristic quantities of the vessel structure are determined in order to be able to detect anomalies.
2. Description of the Prior Art
Modern three-dimensional imaging methods in medicine enable the detection and display of vessel structures of a patient, both in three-dimensional perspective and in cross-section perspective in arbitrarily selectable slice planes. By quantitative evaluation of the 3D volume data set acquired with the imaging methods, vessel structures can be measured and relevant characteristic quantities of these vessel structures can be determined. Such characteristic quantities can be, for example, the course of the vessel cross-section, the vessel segment length, vessel branchings or the curve of the vessel. These characteristic quantities can be automatically acquired from the volume data set by data processing and can be used to detect vessels with pathological abnormalities. Of particular importance are hereby vessel narrowings (stenoses) and vessel widenings (aneurysms).
German Translation 695 22 844 deals with the problem of the detection of anomalies such as stenoses using angiographs of the human or animal body. The concern of this publication, however, is not the detection of anomalies, but rather skeletonization of the vessel structures from two-dimensional angiography images as well as the determination of the width of the vessel structures along its course. The method proposed in the printed publication should automatically enable a precise determination of these features of the vessels.
PCT Application WO 00/45326 describes a method for automatic localization and extraction of curves in images, in particular of anatomical structures in medical images, in which dynamic programming is used to localize the curves. No detection of anomalies in vessel structures is undertaken with the method.
U.S. Pat. No. 5,891,030 discloses a method for visualization of tube-shaped structures of a patient using a CT system. In this method, the center line of the tube-shaped structure is determined in the CT images in order to generate based on this different image representations of the tube-shaped structure. This publication also does not deal with the detection of anomalies in vessel structures.
To detect anomalies in vessel structures from 3D volume data sets, it is necessary to compare the determined characteristic quantities with reference quantities in order to be able to decide about the existence or nonexistence of an anomaly. In conventional applications, these reference quantities have to be manually determined in order to be able to effect a quantification (for example of the degree of a stenosis) of a vessel section established by the user. This known technique of the detection of anomalies using the image date is, however, very complicated.